Code Blue is generally used to indicate a patient requiring immediate resuscitation, most often after suffering a cardiac arrest. Code Red is used to define a possible fire in the hospital.

Code Blue! Code Yellow! Code Silver! Quick, how many of those hospital alerts do you know? Even as a longtime viewer of medical dramas like “Grey’s Anatomy,” “ER” and, yes, “Code Black ...

The zoo determines whether to issue a code red or blue depending on the level of safety and concern around the missing animal, a zoo spokeswoman said.

When Code Blue warnings are in effect, anyone in New York in need of assistance has access to emergency shelters. The city also ramps up its homeless outreach efforts. Last night, for instance ...